Hormones & Signal Transduction 5 Sections28 LessonsLifetime

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Lecture 01
2 Items
- 1.1
  Introduction to Hormones
- 1.2
  Signal Transduction – Hormones
Signaling and Signal Transduction
7 Items
Hypothalamic & Pituitary Hormones
3 Items
In this section we will discuss the hypothalamic endocrine control on varoius hormones secretin. After that the hormones of the posterior pituitary gland, the antidiuretic hormone and oxytocin, will be discussed individually.
Hormones of the Anterior Pituitary Gland
12 Items
Here we will discuss the Hormones of Anterior Pituitary gland, their secretion, functions and control in various organs
Steroid Hormones
4 Items
This section will be on the steroid hormones, their synthesis, secretion, transport, actions on different organs, mechanism of action of steroid hormones, abnormalities of steroid hormones and their management.

Oxytocin – Posterior pituitary hormones

In humans, oxytocin acts primarily on the breasts and uterus.

Oxttocin is also involved in luteolysis as well.

G-protein-coupled (PIP2) oxytocin receptor has been identified in human myometrium.

A similar or identical receptor is found in mammary tissue and the ovary.

It triggers increases in intracellular Ca²⁺ levels.

Oxytocin causes contraction of the myoepithelial cells that line the ducts of the breast.

This squeezes the milk out of the alveoli of the lactating breast into the large ducts (sinuses) & thence out of the nipple (milk ejection).

Oxytocin causes contraction of the smooth muscle of the uterus.

The sensitivity of the uterine musculature to oxytocin is enhanced by estrogen & inhibited by progesterone.

In males it is involved in ejaculation.